Beginner's help with topology? (Extruding and beveling letters)
You have 2 ways:
Converting your letters to mesh and working the topology so that it works fine when you bevel, but in your case it's more a matter of how your topology is than a problem of tris and ngons. Here I've made a X &gt; Limited Dissolve and tried a bevel, then create new edges where I saw that the bevel failed:


Or keeping your letter vectorial and giving it extusion and bevel in the Properties panel &gt; Object Data &gt; Geometry, then converting it to mesh (then, same thing, you can simplify the topology with a X &gt; Limited Dissolve):